Conventional databases are capable of holding thousands of data records. One growing class of databases are CD-ROM (Compact Disk-Read Only Memory) storage systems. In CD-ROM storage, the data records are fixed and cannot be dynamically altered. CD-ROM storage systems are a very useful storage medium for holding historical data, research data, and the like.
In any database system, such as a CD-ROM storage system, it is a normal and desirable function to be able to search for certain data records. When a request is made for an individual record, the search typically involves comparing each data record with the request until the desired record is located. Once the record is located, the search is terminated.
It is often desirable to search for not just one record, but for a group of records that satisfy a set of search criteria. When a request is made to search for data records satisfying a criteria, conventional databases again conduct a record-by-record comparison. Those records satisfying the criteria are kept and those records that fail the criteria are rejected. This iterative process is continued through the entire database to ensure that no data records are overlooked.
As databases evolve to hold more and more records, the iterative record-by-record comparison is increasingly unsatisfactory because it requires significant time and processing resources. To search a single CD-ROM holding thousands of records, a common search time for a group of criteria-satisfying data records might be a few seconds. To search larger databases, the time can be even longer.
It is therefore an objective of this invention to devise a database search technique which performs a group search function in a more instantaneous time frame.